This invention relates to weight measuring and value computing apparatus and more particularly to improved apparatus for weighing, computing a value and printing an article label showing the weight, price per unit weight and computed value of in of a plurality of successive articles. The
In recent years the demand for increased efficiency has created the need for high speed measuring apparatus capable of automatically weighing successive articles and, for each weighed article, computing a value based upon a predetermined price per unit weight and printing an article label bearing such weight, price per unit weight and computed value. Such measuring apparatus is commonly used, for example, in supermarket meat departments. After a butcher cuts and divides meat into package portions, the meat may be automatically packaged and subsequently labeled by automatic weight measuring, value computing and label printing apparatus.
In the past, apparatus for weighing an article, computing an article value and printing an article label have included a combination of mechanical, optical and electrical elements. A typical prior art system of this type is described in U.S. Pat. No. 3,384,193 which issued on May 21, 1968 to William C. Susor et al and U.S. Pat. No. 3,453,422 which issued on July 1, 1969 to William C. Susor. This system includes a mechanical-optical scale which generates a digital signal corresponding to an article weight. A computer multiplies the measured weight by a price per unit weight, using a partial products method of multiplication, to obtain the article's value. The measured weight data, the price data and the computed value data are then supplied to a printer for producing an article label. the system is provided wtih various interlocks which reduce the chances of printing erroneous labels or multiple labels for a single article. For example, if the price per until weight or the tare weight data are changed, a "lock" switch must be manually pushed to prevent accidental changes in this data. A label cannot be printed if the weight or the computed value exceed the capability of the system. After a label is printed, another interlock prevents printing the next label until printed label is removed from the printer for application to the article. The system also includes a scale motion detector which inhibits printing a label unit the measured weight reaches a steady state.
Prior art weighing and value computing systems generally include means for compensating the measured gross weight for the tare weight of a container holding the article being priced. The tare weight is often entered manually through a plurality of switches. In one prior art embodiment, the tare weight is entered through a plurality of ten positioned rotary switches, with each switch representing a different decade of the tare weight. However, a system of this type may provide inaccurate weight and value data because of the opportunity for failure on the part of the operator to enter the correct tare weight for each article. Once the rotary switches are set to a tare weight, they will remain set until manually changed by the operator. If a series of articles in containers having different tare weights are being weighed and priced, the operator may forget to update the tare weight for each successive article. The net weight and computed value for the article will then be based upon an incorrect tare weight. Various other switch arrangements have also been suggested in the prior art for manually entering tare weight data into a scale system. Many of these systems are subject to human errors on the part of the system operator.